The invention relates in general to insensitive munitions, and in particular to hand grenades.
A major concern in the field of munition fuzes is the ability of the fuzes to comply with Insensitive Munitions (IM) standards. Stimuli such as impacts from bullets, fragments and shape charges are difficult IM challenges for fuzes, such as grenade fuzes. Known hand grenade fuzes have the fuze primer located in the fuze body and the firing pin located in the rotor assembly.
FIG. 1A is a sectional view of a known grenade fuze assembly 10. Fuze assembly 10 includes a fuze body 12 with a striker lever 14 rotatably mounted thereon. A rotor assembly 16 including a firing pin 18 is rotatably mounted to body 12. A spring 20 torsionally biases rotor assembly 16 in a counterclockwise direction. FIG. 1B shows striker lever 14 and rotor assembly 16 in rotation. FIG. 1C shows firing pin 18 impacting primer 22. The impact of firing pin 18 ignites primer 22. Primer 22 initiates an energetics train 24 disposed in fuze body 12. Energetics train 24 may include, for example, a delay mix 26, lead styphnate 28, lead azide 30, and RDX 32, as referenced in FIGS. 1A, 1C, 2A, and 4.
Even if striker lever 14 and rotor assembly 16 are secured in the unarmed state of FIG. 1A using a pull pin (not shown), primer 22 may ignite if impacted by a bullet, fragment, or shape charge, thus creating a shock-induced catastrophic initiation. The initiation is catastrophic because, in grenade fuze assembly 10, primer 22 is in line with energetics train 24.
A need exists for a grenade fuze assembly that is less sensitive to impacts from, for example, bullets, fragments, or shape charges.